TSSERVER: import {…} from '//some/path' chokes tsserver/code (overloads CPU)

[SMotaal]

TypeScript Version(s): 2.7.0-rc 2.7.2 2.8.0-dev***

Search Terms: tsserver overloads ………………………

Code

// helpers.m.js
export { html, render } from '//node_modules/lit-html/lib/lit-extended.js';

Expected behavior:

Resolve at best, report issue at worse.

Actual behavior:

VS Code's tsserver sub process overloads CPU (sometimes 101% whatever that is)

Workaround:

This makes VS Code happy, but makes the code less compatible with requirements.

// helpers.m.js
export { html, render } from '/node_modules/lit-html/lib/lit-extended.js';

Playground Link:

Related Issues:
#21274

[DanielRosenwasser]

Can you please elaborate on what your file system looks like? // is seen as a network path; is that what you're intending?

[SMotaal]

I'm on a macOS 10.13.3 (17D102)

Volume type: APFS Volume
BSD device node: disk1s1

Workspace path is a "no-spaced" path like /Users/XX/Projects/XX-js/modules/module-name/ and I got rid of all ts/jsconfig files.

The runtime is not relevant and is not a factor since simply switching from //node_modules/… to something like app:node_modules/… or whatever://… or even just /node_modules/… seems to resolve the issue instantaneously most of the time or as soon as the tsserver restarts if it was too draining.

So, to reiterate, no possible configuration (ie ts/jsconfig) had any impact on this bug and there are no special path aspects (not even a single symlink in any of the search paths.

[SMotaal]

Some "good" code --status (without the //node_modules/… specifier):

Version:          Code 1.21.0 (9a199d77c82fcb82f39c68bb33c614af01c111ba, 2018-03-07T10:54:22.798Z)
OS Version:       Darwin x64 17.4.0
CPUs:             Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz (8 x 2600)
Memory (System):  16.00GB (4.26GB free)
Load (avg):       2, 2, 2
VM:               0%
Screen Reader:    no
Process Argv:     /Applications/Visual Studio Code.app/Contents/MacOS/Electron

CPU %	Mem MB	   PID	Process
    0	   115	  5238	code main
    0	    98	  5240	   gpu-process
    0	    82	  5242	   shared-process
    0	   229	  5552	   window (helpers.m.js — slicer)
    0	    33	  5558	     terminal
    0	     0	  5559	       /usr/local/bin/zsh -l
    0	    98	  5563	     extensionHost
    0	    98	  5574	       electron_node electronForkStart.js tsserver.js 
    0	    49	  5593	         electron_node typingsInstaller.js tsserver.js typesMap.js 
    0	    49	  5568	     watcherService
    0	    49	  5576	     searchService

Workspace Stats: 
|  Window (helpers.m.js — slicer)
|    Folder (slicer): 20 files
|      File types: js(11) DS_Store(3) json(2) x(2) html(1) lock(1)
|      Conf files: settings.json(1) package.json(1)

Some bad ones:

Version:          Code 1.21.1 (79b44aa704ce542d8ca4a3cc44cfca566e7720f1, 2018-03-14T14:39:09.335Z)
OS Version:       Darwin x64 17.4.0
CPUs:             Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz (8 x 2600)
Memory (System):  16.00GB (4.60GB free)
Load (avg):       2, 2, 2
VM:               0%
Screen Reader:    no
Process Argv:     /Applications/Visual Studio Code.app/Contents/MacOS/Electron

CPU %	Mem MB	   PID	Process
    1	   131	  5973	code main
    0	    98	  5975	   gpu-process
    0	   262	  5976	   window (helpers.m.js — xxx-demo-xxx)
    0	    33	  5983	     terminal
    0	     0	  5984	       /usr/local/bin/zsh -l
    2	   115	  5990	     extensionHost
   99	   131	  6001	       electron_node electronForkStart.js iq.js tsserver.js 
    0	    49	  6020	         electron_node iq.js typingsInstaller.js iq.js tsserver.js typesMap.js 
    0	    49	  6002	       electron_node jsonServerMain.js 
    0	    82	  6003	       electron_node htmlServerMain.js 
    0	    49	  5995	     watcherService
    0	    49	  6005	     searchService
    0	    82	  5977	   shared-process

Workspace Stats: 
|  Window (helpers.m.js — xxx-demo-xxx)
|    Folder (xxx-demo-xxx): 178 files
|      File types: js(74) mjs(25) DS_Store(15) json(9) html(8) css(7) md(5)
|                  ts(4) log(3) lock(3)
|      Conf files: package.json(4) settings.json(2) tsconfig.json(1)

This is the case for both latest code and code-insiders from TS versions 2.7.0-rc 2.7.2 and 2.8 dev.

EDIT: I did remove some project names

[sheetalkamat]

Investigating this..

[SMotaal]

Thanks!